Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
541 FXUS63 KMKX 031551 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 1051 AM CDT Mon Jun 3 2024 .KEY MESSAGES... - Showers and thunderstorms expected to progress eastward late this morning through this evening. There is a conditional (level 2 out of 5, or Slight) risk for severe thunderstorms this afternoon and evening, with wind and hail as the primary threats. - Warm/muggy conditions prevail for the first half of this week. - Additional rounds of showers and thunderstorms Tuesday and Wednesday. - Northwest winds bring cooler and drier air to southern Wisconsin for the second half of this week. && .UPDATE... Issued 1051 AM CDT Mon Jun 3 2024 A line of convection stretching from northern Sauk County to Lafayette County will progress eastward through southwestern Wisconsin this morning into early this afternoon. Southwesterly flow looks to steer storms northeastward along this line, with mesoscale models indicating the majority of convection pushing into central Wisconsin. However, mesoscale modeling is not latching on to the southernmost extent of current convection, leading to concern that far southern Wisconsin will also see storms with this morning to early afternoon round. Hail is the main threat with these storms, as warmer temperatures and clearer skies than previously forecast have increased the instability available. A few gusty winds could not be ruled out, but primarily would be expected in the heaviest thunderstorms where wet microburst potential is maximized. Later this afternoon, expecting a remnant MCV to propagate into central Wisconsin and enhance thunderstorm development across southern Wisconsin. Placement of this enhanced thunderstorm development is still in question, as it will be highly dependent on the placement of lingering boundaries and placements of stable air after the first round of thunderstorms move through. Still anticipating the potential for a few linear segments during the late afternoon and evening hours, bringing additional hail and damaging wind potential. An isolated tornado cannot be ruled out with this activity as the MCV enhances available helicity in the lowest levels. MH && .SHORT TERM... Issued 440 AM CDT Mon Jun 3 2024 Today and Tonight: An MCV currently over northwest Iowa will continue to drift northeastward, working with disorganized nocturnal convection to its north (SE Minnesota and northwest WI) to generate outflow boundaries capable of triggering fresh convection further east (over our CWA) late this morning into this afternoon. SBCAPE up to 2000 joules this afternoon coupled with deep shear of 25 to 45 kts will be sufficient for some organized storm clusters, with some strong to severe storms possible this afternoon and evening. Upscale storm growth and clustering along both remnant and fresh outflow boundaries could lead to training storms (which impact the same area multiple times), capable of a flash flood threat. Hail and damaging wind gusts would be the primary severe weather threats. Isolated tornadoes cannot be ruled out at this time. Storm coverage and intensity is likely to decrease late tonight as instability dwindles. Sheppard && .LONG TERM... Issued 440 AM CDT Mon Jun 3 2024 Tuesday through Sunday: As southerly warm/moist advection continues at the surface, another shortwave trough rotating through the 500mb pattern could trigger warm sector convective initiation, leading to scattered showers and thunderstorms late Tuesday afternoon (40 to 60% chance). However, model guidance suggests that more organized storms will be lined up along the cold front to our west, with 85% precip chances arriving late Tuesday evening through Tuesday night. As the cold front completely crosses the CWA Wednesday morning, precip chances begin a gradual decline (30-60% in the morning), with only 15-30% chances for showers and storms in the cool sector of the parent low pressure (Wednesday afternoon). Cool / dry air advection on northwesterly winds continues through the end of the week, with daytime highs in the low to mid 70s likely for all areas Thursday and onwards. Sheppard && .AVIATION... Issued 1051 AM CDT Mon Jun 3 2024 Southerly winds will continue through today and tonight, with a line of thunderstorms pushing eastward late this morning into this afternoon. Mainly concerned about hail with stronger storms embedded in this line. A few gusts to 25 kt are possible, but unlikely except within the strongest storms. These storms are primarily expected to impact MSN and JVL. An additional round of storms is possible late this afternoon into this evening, with wind and hail expected. These storms are expected to impact MSN, JVL, and SBN in the late afternoon to evening hours, and MKE and ENW in the late evening hours. Overnight, light winds and moisture remaining after storms exit may result in patchy fog development in river valley regions. MH && .MARINE... Issued 440 AM CDT Mon Jun 3 2024 An area of low pressure over southern Alberta to the northern Great Plains deepens to around 29.2 inches today, then drifts northeastward into Ontario through Wednesday. Southerly winds develop today, continuing though Tuesday night. Then a cold front crosses Lake Michigan Wednesday, causing winds to veer westerly. Westerly winds look to continue through the end of the week as the meandering low over south- central Canada weakens to around 29.4 inches. Expect periods of showers and thunderstorms from this afternoon through Wednesday. With humid air moving in from the south today and tonight, fog may develop late tonight through early Tuesday over the waters, and patches of dense fog are possible. Model guidance suggests that northwestern areas of Lake MI will be most susceptible to fog formation. Sheppard && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSMilwaukee www.twitter.com/NWSMilwaukee www.youtube.com/NWSMilwaukee